Seems that there is an uneven top surface. When I flipped this model I had a problem with it not sitting flat on the plate. In fairness, I am using a P1P with a .4 nozzle and a .2 layer height. Not what the model designer had intended, but the top surface of the model should be flat in any case. I fixed this by splitting the model before rotating. I also made the back side of the model all black to save on time and filament waste. Great gift for the holidays though. Well done.